Updated Aug 19/19
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Sonnet Allegro USB 3.1 C-Type 10Gb - $95 - in stock
* Adds Two 10 Gb/s USB Type-C Slots
* Delivers 15W of Power per Port
* Protected Ports
* Resettable Fuses
* PCIe Auto-Negotiation
* Optimized for Thunderbolt
* Easy Installation
Sonnet Allegro USB 3.0 4 Port PCIe Card - $89 - special
Add the speed of USB3 to your Mac Pro tower, or Windows tower, with this inexpensive PCIe card. Gives you four USB3 ports. Also can go into a Thunderbolt PCIe Card Expansion chassis. Requires Mac OS 10.8.5 or later, Windows 7 or later. Warranty - 1 Year.